Primal
by WrathWings
Summary: Dean/Cas, angsty! Spoilers for the latest season.
1. Chapter 1

It starts as a thought lingering in Dean's mind, a single thought that seeps into his dreams and manages to become a fantasy. (He shouldn't say _**a **_because that implies singular and he's had multiple fantasies about Cas; they usually involve handcuffs and doing shameless things to the angel's wings.)

Castiel finds out by accident, attempting to wake Dean from a nightmare only to discover it's quite the opposite. He views Dean's dreams simply to make sure it isn't a bad dream. What he finds there is . . .surprising (he finds a dream version of himself nude beneath Dean, legs identical to his wrapped around the human's waist); the angel moves without thinking. Suddenly, he's halfway across the globe, alone on a mountaintop.

What a curious development.

He understands that humans have basic, primal urges and that sex is included among these, but he never would have thought that he would be the basis of Dean's focus. Still, Castiel knows what is expected of him and he confronts Dean immediately(away from Sam because he knows Dean values his privacy and would find this extremely embarrassing).

Dean, at first, resists nobly, but eventually gives in and kisses the angel. Castiel does not tell Dean that he won't feel any of it; the benefit (or curse) of being an angel is that one doesn't experience human needs or emotions at least not to the extent that actual humans do. But, like a martyr, he bears it in silence as Dean caresses him and lays gentle kisses along his jaw.

He feels something, a sensation, burning under his skin, but he ignores it as Dean strips off their clothes and kisses his lips tenderly. The feeling makes him furious for some reason though he makes sure to keep his face blank as Dean slips his fingers into the angel's body and stretches him open(he wants to tell Dean to stop trying to make him feel it, that he can't and won't-).

Then, the sensation, at first a buzz, now erupts and starts to sear his flesh; Castiel is sinking down on Dean's cock, trying to ignore it when his grace begins to sing. He had placed a piece of his grace in Dean's soul when he rebuilt the human, but now it's as though Dean's soul and Castiel's grace are calling to each other. Pleasure consumes his body as Dean repeatedly strikes his prostate, the human kissing his throat.

_No. _Castiel thinks as he feels his human body react to Dean's touches. _This wasn't supposed to happen. _He briefly wonders what this will mean for them and then tries to not scream as he feels his body tightening; the angel buries his face in Dean's shoulder, trying futilely to keep his grace from bonding even further to Dean's soul when it happens.

His hand seals over the mark on Dean's shoulder and almost in unison, Dean and Castiel release, their graces meeting and if not for their closed eyes, they would have been blinded. The angel is almost thrown from his human vessel and his grip tightens on Dean's flesh, leaving bruises.

When they finally come down, Castiel raises his head and he can feel the bond cementing between them; he meets Dean's eyes, praying that he doesn't feel it. Dean musn't because he leans forward to kiss the angel, but as he does, the bond flares even stronger in Castiel's mind and he runs, spiriting himself away. Naked and shameful, he sits on the mountaintop, with tears in his eyes, blaming himself for this thing he should have seen coming.

_Cas. . ._


	2. Chapter 2

Dean's sitting in another motel room, twirling his cell phone around by the antenna as Sam does research on some ghosts in town. He hasn't seen Cas for days. Normally, it wouldn't bother him, but after what happened, Dean finds himself constantly on edge, snapping at Sam more than usual. Even his brother had been worried when Dean slammed the car door, but it wasn't something he could talk to Sam about.

What he wants is to talk to Cas. What made him run? Was sex with him so terrible? Dean runs a hand over his face and throws the phone down on the table. He hasn't slept in three days(werewolves are bitches to kill) and he needs a nap.

Sam shoots him a look, a variation on the bitch face, but doesn't say anything when he falls to the bed, planning on sleeping for an hour or six. Dean closes his eyes, intending on forgetting Cas and what happened between them.

What happens next is **not **his fault.

Apparently, whatever happened that day with Cas(he's not as dense as everyone thinks; he knows something other than great sex went on) makes it impossible to forget him. The horrible thing is Cas isn't in his dreams and that's why Dean **can't **forget him. Before his dreams were filled with the angel and now there's nothing. He doesn't dream at all. He can't truly describe it because all the words he thinks of pale in comparison. Empty. Hollow. Alone.

In his mind, he's calling to Castiel, but there's nothing. He wakes with the angel's name on the tip of his tongue and Sam's snores echoing in the dark room. Dean clears his throat and whispers for Cas, not even loud enough for it to register in his own ears, let alone to an angel's(to an angel that's probably halfway across the world). When no one answers, Dean Winchester slumps back down onto his pillow and doesn't fall asleep again.

***

The next night, Dean goes to a bar. Sam is back at the hotel (probably looking at porn) and Dean's trying to put off bedtime as much as possible. A promising blonde brushes past him, letting her fingers trail over his neck. His stomach immediately begins churning with disgust and that's when Dean realizes that this thing between him and Cas really is serious.

He can't imagine anyone else's hands on him, doesn't want to, and whenever anyone touches him(or even comes close), the hairs on the back of his neck stand up and every instinct in his mind is screaming for the other half of his goddamn soul(and Dean doesn't want to think about what that means).

Cas needs to be here to explain what's happening. Dean doesn't know if he can wait.

***

Castiel appears four days later looking extremely tired and extremely reluctant to speak to Dean. Much to everyone's surprise, he actually avoids invading Dean's personal space and instead opts to speak only to Sam. Something bubbles in Dean as he watches the angel move closer to someone that isn't him and when Cas moves to put a hand on Sam's shoulder, he finally decides that he's had enough of the games and enough of Castiel's avoidance.

He stalks forward and grabs Cas's hand, sending Sam a look of pure vehemence that his brother takes as his cue to leave. The door closes behind him and there's only silence as the two stare each other down.

"Did I miss something?" Dean's lock on Cas's arm is doing nothing to hold him there; it's the look in the human's eyes that cements the angel there. "Since when are you and my brother best friends?"

"Dean, I was merely-" He's jerked forward, against Dean's chest, and he's so alarmed that he stops speaking.

"No, Cas. Something happened between us and I have a feeling that you know more about it than I do. Feel like sharing with the class?" Dean's body is relaxing in his presence despite his anger and he can feel Cas's breath on his cheek.

The angel shifts and focuses his gaze on something behind Dean's right shoulder. "When I raised you from perdition-" He pauses and Dean nods once, to show that he's listening. "I placed a piece of my grace inside your soul." Cas looks down at his scruffed shoes for a moment. "I was initially instructed not to, but-"

"But what?" Dean leans in a little closer, his eyelids growing heavy; Cas smells. . ._really, really _nice.

"I believed that it would be easier to locate and observe you." There's something in his tone that makes Dean skeptical.

"Is that all?" His nose is right next to the angel's ear and he has the insatiable urge to _**mark **_and _**claim**_.

A heartbeat and then, "Without a fraction of my grace, your body would have been severely weakened. It was necessary to ensure your safety."

Dean stops. Even from the moment they met, Cas only had his best interests at heart. "So what does that mean?" He pulls back and tilts the angel's head up.

"It means, for lack of a better term, that we are bound to each other. Our souls are each other's perfect halves." Castiel, in his defense, seems embarrassed, but this only confirms Dean's suspicions. "I thought it would remain dormant, that it wouldn't have side effects-"

"So you've felt it too?" Dean presses his cheek into Cas's, letting his hands slip around the angel's waist, bringing him closer. "This isn't just me?" He can handle this if Cas is willing to- Oh God. What if Cas **doesn't **want this? Maybe the angel is doing this out of some twisted sense of duty and really thinks Sam is the cute one-

"Yes." Castiel releases a shaky sigh that makes Dean's knees weaker than they should be. "I understand that this is a burden to you; I have been looking for ways to sever-"

"No! No, don't-" Dean cups the angel's face in both hands and kisses him; he doesn't want to hear about ending this when it's the best feeling he's ever had(and he's had plenty of them). Cas's lips feels amazing against his own and it's a wonder they kept apart for a few hours let alone a week and a half.

Cas's hands are squeezing his biceps and Dean pulls away, letting his forehead press against the angel's. Castiel has no way to describe this except _**love. **_"What happens now?"

Sam bursts in. "Dean, we have a- Whoa. Um. Sorry." He's a little shocked to see Dean and Cas so intimately pressed together, but then again, with the mounting sexual tension that's been building, he's not** too **surprised. "We have a nest of vampires in a barn that needs to be taken care of."

Dean sighs and turns to Cas, pressing a chaste kiss to his forehead(much to Sam's dismay). "Right now, we have to save the world." He knows Sam's relieved that the gruesome details have been spared. "And then we can have really kinky sex."

"Dean!" They pile out the door and Castiel lets himself follow beside his beloved. The complicated questions can wait. For now they have each other.


End file.
